Three dimensional lcd monitor display

ABSTRACT

Creating a three dimensional (3D) image on a liquid crystal display (LCD) including providing a light source, a pixel matrix, and a plurality of electrodes for applying a voltage to the pixel matrix. The pixel matrix includes a plurality of first pixels having a first polarization and a plurality of second pixels having a second polarization. A first light is emitted from the light source, and first voltage is applied to at least one of the plurality of first pixels. A second light is emitted from the second light source and a second voltage is applied to at least one of the plurality of second pixels.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/357,707, filed Jan. 25, 2012, the content of which is herebyincorporated by reference in its entirety.

BACKGROUND

The present invention relates to an LCD monitor, and more specifically,to a three dimensional LCD monitor usable with passive glasses.

Three dimensional (3D) movies and pictures have become a popular form ofentertainment due to the increased realism of the images. 3D imagesutilize the human physical trait of binocular vision. Human eyes arespaced about two inches (five centimeters) apart, therefore each eyesees the world from a slightly different perspective. The brain receivesboth images and has a binocular vision function that correlates thedifference between what each eye sees to determine distance. Thedetermination of the distance provides the 3D effect that a person sees.

To create a binocular image on a two dimensional (2D) surface, such as amovie or television screen, the user typically wears glasses. Theglasses alter the way that the user views the images to create thesimulated 3D effect. Typically there are two types of glasses, passiveglasses and active glasses. The type of glasses used will depend on thetype of image projection system being used.

Passive glasses rely upon an optical effect created by using differentlenses for each eye. The display device emits a sequential series ofimages where subsequent images are slightly offset. The images arearranged such that the user sees the first image through a first lens ofthe glasses (e.g. the right eye) and the second image is seen with theother lens (e.g. the left eye). Since the images are projected quickly,the user does not notice the multiple images, but rather sees a 3Deffect. Originally, passive glasses used different color lenses tofilter out images; however this limited the use of 3D images when fullcolor images were desired. To alleviate this issue, polarized lenseswere developed where each lens of the glasses allows the transmission ofdifferent polarized light. The polarized passive lenses allow for fullcolor 3D images to be transmitted.

In systems using active glasses, the glasses wirelessly communicate withthe display device to synchronize the operation of the glasses with theimages being displayed. With active glasses, the lenses are typicallyliquid crystal displays (LCDs) that can switch between transmittinglight and blocking light. In this way, the glasses may rapidly switchthe left and right lenses between clear and opaque. While the glassesare switching, the television is projecting a series of sequentialimages. When this switching is synchronized between the television andthe glasses, the user experiences a 3D effect.

BRIEF SUMMARY

An embodiment is a method for creating a three dimensional (3D) image ona liquid crystal display (LCD). The method incudes providing a lightsource, a pixel matrix, and a plurality of electrodes for applying avoltage to the pixel matrix. The pixel matrix includes a plurality offirst pixels having a first polarization and a plurality of secondpixels having a second polarization. A first light is emitted from thelight source, and first voltage is applied to at least one of theplurality of first pixels. A second light is emitted from the secondlight source and a second voltage is applied to at least one of theplurality of second pixels.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The forgoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 is an exploded view of a conventional liquid crystal display(LCD) monitor;

FIGS. 2A and 2B are a schematic view of a pixel in an LCD monitor inaccordance with an embodiment of the invention;

FIGS. 3A and 3B are a schematic view of a pixel in an LCD monitor inaccordance with an embodiment of the invention;

FIG. 4 is a schematic view of a matrix of an LCD monitor in accordancewith an embodiment of the invention;

FIG. 5 is a schematic view of an alternate matrix of an LCD monitor inaccordance with an embodiment of the invention;

FIG. 6 is an exemplary matrix with connected electrodes of an LCD inaccordance with an embodiment of the invention; and

FIG. 7 is a flow chart describing a method of operating a threedimensional (3D) image projector with two color imaging in accordancewith an embodiment of the invention.

DETAILED DESCRIPTION

Embodiments described herein include liquid crystal displays (LCDs) thatare modified by using multiple liquid crystal cells which arealternately polarized for left and right eye views to allow astereoscopic three dimensional (3D) image to be viewed with passivepolarized eyewear. This approach doubles the number of pixels in thedisplay, or alternately, reduces the resolution of a standard sizescreen by reusing half of the pixels to transmit redundant information.In an embodiment, the pixels are addressed by an x-y grid of electrodesand can be actuated sequentially to project alternate polarization leftand right eye image components for each of the primary colors (red,green, blue or “RGB”). When viewed with passive eyewear, a 3Dstereoscopic image is presented to the viewer. As described herein, inembodiments a pattern is used to excite the electrodes in an LCD displaysuch that the polarized 3D information is generated efficiently for highspeed modulation at twice the video frame rate of the LCD display. Asused herein, the term “frame rate” refers to the frequency at which animaging device (e.g., an LCD screen) produces unique consecutive imagescalled frames. Frame rate is most often expressed in frames per second(FPS). Embodiments also include liquid crystal elements in the displayhaving an increased thickness such that the degree of polarizationrotation can be controlled effectively to produce polarized light for 3Dimaging.

Embodiments, allow a 3D image to be viewed on a LCD screen using passivepolarized eyewear. The use of passive polarized eyewear has severalbenefits when compared with using active glasses to view 3D images on aLCD screen. While active glasses perform well to create the 3D effectfor the user, they also have some less desirable characteristics. Forexample, active glasses require an energy source such as a battery thatneeds to be periodically recharged or replaced. In addition, if thecommunication between the television and the glasses is interrupted, the3D effect may be lost. Further, due to the complexity of the system,active glasses tend to be much more costly than passive glasses.

With reference to FIG. 1, a conventional backlit LCD monitor 10 isgenerally shown. The LCD monitor 10 includes a liquid crystal layer 20having liquid crystal molecules, or pixels, formed in a matrix. Theliquid crystal layer 20 is surrounded on each side by an electrode 22,24. Adjacent to each electrode 22, 24 is a respective polarizing filter26, 28 that allows only light of a specific polarization to passthrough. A light source 16, such as a fluorescent lamp, may be used toproduce light within the LCD monitor 10. In an alternate embodiment, theLCD monitor is reflective such that instead of a light source 16, themonitor 10 includes a minor to reflect external light. As the lightpasses through the first polarizing filter 26 in the direction of arrow30, the light becomes polarized. Before applying an electric charge, theorientation of the liquid crystal molecules of the liquid crystal layer20 is determined by the alignment at the surfaces of electrodes 22, 24.Commonly in LCD devices, liquid crystal molecules align perpendicularlyat the two electrodes 22, 24 causing the molecules to arrange themselvesin a helical structure. The surface of each electrode 22, 24 contactsthe liquid crystal layer 20, and applies a voltage or charge to aparticular liquid crystal molecule or group of liquid crystal moleculesso as to “twist” the liquid crystal molecules in a particular direction.By controlling the voltage applied across the liquid crystal layer 20 ineach pixel, light can be allowed to pass through in varying amounts.

Application of a voltage to an already polarized pixel will rotate thepolarization of the pixel 90 degrees. Referring now to FIG. 2A, a pixel40 within the liquid crystal layer 20 of FIG. 1 is shown. The initialpolarization of the pixel 40 is depicted by the vertical arrow 42. In anexemplary embodiment of the present invention, electrodes 22, 24intersect at a corner of the pixel 40. In alternate embodiments, the twoelectrodes 22, 24 intersect at any point within the pixel 40. When avoltage is applied to the electrodes 22, 24, the direction ofpolarization of the pixel 40 is altered. FIG. 2B represents the samepixel 40 displayed in FIG. 2A after a voltage has been applied. Thearrow 42 representing the direction of polarization of the pixel 40 hasrotated 90 degrees such that the pixel 40 is now horizontally polarized.Similarly, referring to FIG. 3A, a pixel 40 is shown having an initialhorizontal polarization. Once a voltage is applied to the electrodes 22,24, the polarization of the pixel 40 converts to a vertical polarizationas shown in FIG. 3B.

With reference to FIGS. 4 and 5, every liquid crystal molecule in an LCDdevice has both a color and a polarization. In one embodiment of thepresent invention, each pixel in the LCD device comprises a singleliquid crystal molecule. In an alternate embodiment, a pixel 40comprises a plurality of liquid crystal molecules. If a pixel 40 doescomprise more than one liquid crystal molecule, the plurality of theliquid crystal molecules within the pixel are the same color and arepolarized in the same direction. As shown in embodiment in FIG. 5 forexample, the three red liquid crystal molecules on the left-hand side ofthe pixel matrix 50 have the same polarization and therefore may beconsidered one pixel.

A pixel matrix 50 includes a plurality of first pixels 40 having a firstpolarization and a plurality of second pixels 40′ having a secondpolarization. In one embodiment of the invention, the first polarizationand the second polarization are orthogonal. Consequently, the pluralityof first pixels 40 having a first polarization emit an image viewable bya first eye, such as a left eye, and the plurality of second pixels 40′having a second polarization emit an image viewable by a second eye, aright eye for example. The plurality of first pixels 40 may include aplurality of colors and the plurality of second pixels 40′ may includethe same plurality of colors as the plurality of first pixels. Forexample, the plurality of colors of both the first pixels and secondpixels may include red, green and blue. In a pixel matrix 50, the pixelsare arranged such that along a row, pixels alternate between the pixelshaving a first polarization and pixels having a second polarization. Forexample, a pixel from the plurality of first pixels 40 is adjacent apixel from the plurality of second pixels 40′. Orthogonally polarizedpixels 40, 40′ are additionally grouped into pairs of pixels of the samecolor. A pair of orthogonally polarized pixels 40, 40′of a first colormay not be disposed adjacent another pair of pixels of the same firstcolor. As shown in FIG. 4, the colors of the pairs of pixels alternatealong a row such that two pairs of pixels of the first two colors (e.g.,R, G) are disposed between two pairs of orthogonally polarized pixels ofthe third color (e.g., B).

In an embodiment, in order to project a 3D image, the frame rate atwhich images are projected from the LCD monitor is doubled aconventional frame rate since both a left eye and right eye image mustbe emitted in the same time that a regular image would be projected. Apixel matrix 55 according to one embodiment of the invention is shown inFIG. 6. This exemplary pixel matrix 55 portrays the placement of aplurality of electrodes to apply a voltage to the pixels of a firstcolor, for example red, from both the plurality of first pixels 40 andthe plurality of second pixels 40′. Horizontal electrodes are locatedadjacent the pixel matrix 50 at the intersection of adjacent verticalpixels. In this exemplary embodiment, the pixels 40 are energized in thelower left corner; in other embodiments, the pixels may be energizedother locations. Vertical electrodes 60, 62 are disposed along avertical edge of each red pixel such that the vertical electrode 60, 62intersects a horizontal electrode 64 at a corner of a red pixel.Vertical electrodes 60 must intersect horizontal electrodes 64 at acorner of each red pixel from the plurality of first pixels 40 andvertical electrodes 62 must intersect horizontal electrodes 64 at acorner of each red pixel from the plurality of second pixels 40′. Avoltage is applied to pixels of a first color from the plurality offirst pixels 40 through the intersection of electrodes 60 and 64. Forexample, a voltage is first applied to red pixels polarized to projectan image viewable by the left eye. Application of the voltage alters thepolarization of these first pixels 40 such that light of a certainpolarization will be transmitted through the pixels. Sequentially, avoltage is applied at the intersection of the vertical electrodes 62 andthe horizontal electrodes 64 to pixels of a first color from theplurality of second pixels 40′, such as red pixels polarized to projectan image viewable by the right eye.

Embodiments are not limited to the configuration shown in FIG. 6. Inother embodiments. For example, the order of the red, green, and bluepixels can be altered to any desired configuration and is not limited tothe representation shown in FIG. 6. Further, the pixels may be arrangedsuch that the vertical and horizontal electrodes intersect at any partof the pixel, not just the corner of the pixel illustrated in FIG. 6.Further, the location of the left and right eye views for each colorpixel may be altered to any desired configuration and is not limited tothe representation shown in FIG. 6.

Referring now to FIG. 7, a method 70 is shown for projecting a threedimensional image from an LCD monitor, such as LCD monitor 10. To createthe first image in block 80, a light source, such as light source 16,emits a first light in the direction of the liquid crystal layer 20. Inblock 84, a first voltage is applied by intersecting electrodes, such aselectrodes 60, 64, to the plurality of first pixels 40 of a same firstcolor, for example red. By applying a voltage to these first pixels 40of a first color, the polarization of the pixels is rotated, and animage of a first color, viewable by a first eye, such as a left eye, isprojected from the monitor 10 in block 86. Sequentially, a second imagein block 90 is created by projecting a second light from the lightsource, as in block 92. A second voltage is applied in block 94 to aplurality of second pixels 40′ of the same first color as the pluralityof first pixels 40 in block 84. Similar to the first pixels 40, theelectric charge causes the polarization of the second pixels 40′ of afirst color to rotate such that a second image is emitted as shown inblock 96; the image being the same first color and viewable by a secondeye, such as a right eye.

Once an image has been projected by applying a voltage to both theplurality of first pixels 40 of a first color and the plurality ofsecond pixels 40′ of a first color, an image is created in block 100using pixels of a second color from the plurality of first pixels 40.The light source 16 emits a third light in block 102. In block 104, athird voltage is applied to the plurality of first pixels 40 having asecond color, such as green, to change the polarization of these pixels.The third light passes through the open pixels of the pixel matrix 50,thereby emitting an image of a second color viewable by the first eye.In block 110, the image of a second color viewable by the second eye iscreated. The fourth light from light source 16 is emitted, as shown inblock 112, and a fourth voltage is applied to the plurality of secondpixels 40′ having the same second color as the plurality of first pixels40 in block 104. Application of the voltage alters the polarization ofthe charged pixels, and an image of a second color viewable by thesecond eye is emitted from the monitor 10. Similarly, a pair of imagesof a third color, viewable by the first and second eye, is thensequentially emitted as shown in blocks 120, 130. In block 122, a fifthlight is emitted, and in block 124 a fifth voltage is applied to pixelsof a third color, for example blue, from the plurality of first pixels40 to project an image of a third color viewable by the first eye. Afterthe first eye image of a third color is emitted, a sixth light isemitted as shown in block 132. Similarly a sixth voltage is applied tothe pixels of the third color from the plurality of second pixels 40′,and an image of a third color viewable by the second eye is projectedfrom the monitor 10. Once images for the plurality of colors have beenprojected in pairs for both the first and second eyes, the method 70then loops back to block 80 to continue projecting images from themonitor 10 in the color sequence. The frame rate of all six of theseimages that are projected from the LCD monitor is doubled in comparisonto a conventional frame rate since both a left eye and right eye imagemust be emitted in the same time as a regular image.

In an alternate embodiment of the invention, all of the images viewableby the first eye are projected before the images viewable by the secondeye are projected. Pixels of a first color from the plurality of firstpixels 40 are charged to emit a first image. Instead of then projectingan image using the pixels of the same color from the plurality of secondpixels 40′, an image is created by applying a voltage to pixels of asecond color from the plurality of first pixels 40. An image will becreated for each color of the plurality of colors of the plurality offirst pixels 40. Once all of the first eye images have been emitted,images for the second eye will then be projected in the same colorsequence. For example, if a red image, a green image, and then a blueimage were projected viewable by the left eye, a red image, green imageand then a blue image will be projected in that order viewable by theright eye. Similar to the alternate projection sequence previouslydiscussed, all six of these images must be projected within the sametime that a regular image is projected.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of onemore other features, integers, steps, operations, element components,and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

The flow diagrams depicted herein are just one example. There may bemany variations to this diagram or the steps (or operations) describedtherein without departing from the spirit of the invention. Forinstance, the steps may be performed in a differing order or steps maybe added, deleted or modified. All of these variations are considered apart of the claimed invention.

While the preferred embodiment to the invention had been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the invention first described.

1. A method for creating a three dimensional (3D) image on liquidcrystal display (LCD), the method comprising: providing a light source;providing a pixel matrix having a plurality of first pixels having afirst polarization and a plurality of second pixels having a secondpolarization; providing a plurality of electrodes for applying a voltageto the pixel matrix; emitting a first light from the light source;applying a first voltage to at least one of the plurality of firstpixels; emitting a second light from the light source; and applying asecond voltage to at least one of the plurality of second pixels.
 2. Themethod of claim 1, wherein each pixel in the plurality of first pixelsand the plurality of second pixels comprises a single liquid crystalmolecule.
 3. The method of claim 1, wherein each pixel in the pluralityof first pixels and the plurality of second pixels comprises multipleliquid crystal molecules.
 4. The method of claim 1, wherein each pixelin the plurality of first pixels and the plurality of second pixelscomprises a plurality of liquid crystal molecules of the same color. 5.The method of claim 1, wherein the plurality of first pixels comprisespixels of a plurality of colors and the plurality of second pixelscomprises pixels of the plurality of colors.
 6. The method of claim 5,wherein the first voltage is applied to at least one of the plurality offirst pixels having a first color, and the second voltage is applied toat least one of the plurality of second pixels having the first color.7. The method of claim 6, further comprising: emitting a third lightfrom the light source; applying a third voltage to at least one of theplurality of first pixels having a second color; emitting a fourth lightfrom the light source; and applying a fourth voltage to at least one ofthe plurality of second pixels having the second color.
 8. The method ofclaim 7, further comprising: emitting a fifth light from the lightsource; applying a fifth voltage to at least one of the plurality offirst pixels having a third color; emitting a sixth light from the lightsource; and applying a sixth voltage to at least one of the plurality ofsecond pixels having the third color.
 9. The method of claim 8, whereinthe LCD is characterized by a frame rate, and the applying the firstvoltage, applying the second voltage, applying the third voltage,applying the fourth voltage, applying the fifth voltage, and applyingthe six voltage occurs at twice the frame rate.
 10. The method of claim1, wherein the first polarization is orthogonal to the secondpolarization.
 11. The method of claim 1, wherein the 3D image isconfigured for viewing with passive eyewear.